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Abstract:

Embodiments of the invention provide fiber mat facers, ceiling panels,
and method of manufacturing the same. A fiber mat facer may include a
non-woven web of fibers having a first group of fibers with an average
fiber diameter from about 6 μm to about 20 μm and a second group of
fibers with an average fiber diameter from about 0.5 μm to about 5
μm. The fiber mat facer may also include a binder to bond together the
non-woven web of fibers into the fiber mat. The binder may include a
water repellant additive. The binder and/or fiber mat facer may further
include an additive that enhances the opacity of the fiber mat facer. The
fiber mat facer may also include a paint applied to an outer surface of
the facer. The paint may include an additive that enhances the visual
appeal of the facer and/or ceiling panel.

Claims:

1. A fiber mat facer comprising: a non-woven web of fibers comprising: a
first group of fibers having an average fiber diameter from about 6 μm
to about 20 μm; and a second group of fibers having an average fiber
diameter from about 0.5 μm to about 5 μm; a binder to bond together
the non-woven web of fibers into the fiber mat, the binder including a
water repellant additive; and an additive that enhances the opacity of
the mat.

2. The fiber mat facer of claim 1, wherein the fiber mat facer further
comprises a stearylated melamine water repellant.

3. The fiber mat facer of claim 2, wherein the stearylated melamine water
repellant comprises between about 0.4 wt. % and 1.5 wt. % of the total
weight of the fiber mat.

4. The fiber mat facer of claim 1, further comprising a paint atop an
outer surface of the fiber mat, the paint comprising a weak acid.

5. The fiber mat facer of claim 4, where in the weak acid comprises one
or more acids selected from the group consisting of: sodium
tetrafluoroborate; boric acid; and sodium hypochlorite.

6. The fiber mat facer of claim 1, wherein the binder comprises an amount
of an anti-oxidant.

17. A faced ceiling panel comprising: a fiber mat facer affixed to at
least one surface of the ceiling panel, the fiber mat facer comprising: a
non-woven web of fibers comprising: a first group of fibers having an
average fiber diameter from about 6 μm to about 20 μm; a second
group of fibers having an average fiber diameter from about 0.5 μm to
about 5 μm; an acrylic binder to bond together the non-woven web of
fibers, the acrylic binder including a water repellant additive; and an
additive that enhances the opacity of the fiber mat facer.

Description:

[0001] This application is a division of pending U.S. Ser. No. 13/557,274
filed Jul. 25, 2012, the entire disclosure of which is hereby
incorporated by reference herein.

BACKGROUND OF THE INVENTION

[0002] The present invention generally provides fiber mat facers that may
be coupled with a ceiling panel to enhance the visual appeal of the
ceiling panel, and more specifically provides fiber mat facers of various
compositions described herein that enhance the visual appeal of the
facers and, thus, the ceiling panels.

[0003] Facer products made of mats of bonded fibers are often attached to
ceiling panels to enhance the aesthetic appeal, strength, sag resistance,
and/or flame resistance of the ceiling panels. The ceiling panels are
then often installed in suspended ceilings by inserting the ceiling
panels into frames of the suspended ceiling. The facer products are
attached to the side of the ceiling panel facing the room's interior so
as to enhance the aesthetic appearance of the room. Since the ceiling
panels will be used for perhaps many years and continually viewed during
that period of time, it is important that the facer products attached to
the ceiling panels be durable and provide long lasting visual appeal.
Accordingly, there is a constant need for improved facer products that
may be attached to ceiling panels that provide long lasting visual
appeal.

BRIEF SUMMARY OF THE INVENTION

[0004] Embodiments of the invention generally provide fiber mat facers,
ceiling panels, and methods of making the same that enhance the visual
appeal of rooms in which the ceiling panels and facers are installed.
According to one embodiment, a fiber mat facer is provided. The fiber mat
facer may include a non-woven web of fibers that includes a first group
of fibers having an average fiber diameter from about 6 μm to about 20
μm and a second group of fibers having an average fiber diameter from
about 0.5 μm to about 5 μm. The fiber mat facer may also include a
binder to bond together the non-woven web of fibers into the fiber mat.
The binder may include a water repellant additive. The fiber mat facer
and/or binder may further include an additive that enhances the opacity
of the mat. In one embodiment, the additive that enhances opacity may
include white pigment added to the binder and/or fiber mat facer.

[0005] The binder may also include a water repellant additive, which in
one embodiment includes a stearylated melamine water repellant. In
another embodiment, the binder includes a hexamethoxymethylolmelamine
crosslinking agent. Paint may be applied to or atop an outer surface of
the fiber mat. The paint may include a weak acid, which in one embodiment
includes: sodium tetrafluoroborate, boric acid, and/or sodium
hypochlorite. The binder may further include an amount of an
anti-oxidant, such as sodium tetrafluoroborate.

[0006] In one embodiment, the first group of fibers have an average fiber
diameter of about 11 μm and the second group of fibers may have an
average fiber diameter of about 3 μm. The large diameter fibers and/or
microfibers may include glass fibers such as E glass, C glass, T glass,
sodium borosilicate glass, and the like, and mixtures thereof.

[0007] Exemplary compositions of the fiber mat facer may include white
pigment between about 0.5 wt. % and 2.0 wt. % of the total weight of the
fiber mat, the first group of fibers between about 60 wt. % and 71 wt. %
of the total weight of the fiber mat, the second group of fibers between
about 5 wt. % and 20 wt. % of the total weight of the fiber mat, the
binder between about 15 wt. % and 25 wt. % of the total weight of the
fiber mat, and/or the stearylated melamine water repellant between about
0.4 wt. % and 1.5 wt. % of the total weight of the fiber mat. It should
be realized that the fiber mat facer need not necessarily include each of
the above components or include the components within the above-defined
ranges. For example, some facers may include one or more of the above
described components and/or one or more of the components within the
above described ranges, while not including one or more of the other
components, or while including one or more of the other components in a
range other than that described.

[0008] According to another embodiment, a faced ceiling panel is provided.
The faced ceiling panel may include a fiber mat facer affixed to at least
one surface of the ceiling panel. The fiber mat facer may be any of those
described herein, such as including a non-woven web of fibers including:
a first group of fibers having an average fiber diameter from about 6
μm to about 20 μm, a second group of fibers having an average fiber
diameter from about 0.5 μm to about 5 μm, an acrylic binder to bond
together the non-woven web of fibers, the acrylic binder including a
water repellant additive, and an additive that enhances the opacity of
the fiber mat facer. The ceiling panel may be a panel made of glass wool,
mineral wool, fiberboard, wet felt, wood fibers, gypsum, and the like. In
one embodiment, the fiberboard ceiling panel may have a composition of
mineral wool, perlite, and newsprint fibers coated with a
styrene-acrylate copolymer binder and may also include silica alumina
extender particles.

[0009] According to another embodiment, a method for manufacturing a fiber
mat facer is provided. The method may include blending a first group of
fibers having an average fiber diameter from about 6 μm to about 20
μm with a second group of fibers having an average fiber diameter from
about 0.5 μm to about 5 μm to form a non-woven web of fibers. The
method may also include contacting the non-woven web of fibers with a
binder solution to form a wet mat. The binder solution may include a
water repellant additive and an additive that enhances the opacity of the
fiber mat facer. The method may further include curing the wet mat to
form a fiber mat. The method may additionally include applying paint to
an outer surface of the fiber mat and, optionally, mixing a weak acid
with the paint prior to applying the paint to the outer surface of the
fiber mat.

[0010] The weak acid that is mixed with the paint may include sodium
tetrafluoroborate, boric acid, sodium hypochlorite, and the like. The
binder may include a stearylated melamine water repellant additive. The
binder may also include sodium tetrafluoroborate that reduces yellowness
of the fiber mat facer and/or applied paint. In one embodiment, the first
group of fibers may have an average fiber diameter of about 11 μm
and/or the second group of fibers may have an average fiber diameter of
about 3 μm. In one embodiment, the additive that enhances the opacity
of the fiber mat facer may include a white pigment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention is described in conjunction with the appended
figures:

[0012] FIG. 1 illustrates a perspective view of a fiber mat facer
according to an embodiment of the invention.

[0013] FIG. 2 illustrates a perspective view of the fiber mat facer of
FIG. 1 coupled with a ceiling panel according to an embodiment of the
invention.

[0014] FIG. 3 illustrates a method for manufacturing a fiber mat facer
according to an embodiment of the invention.

[0015] FIG. 4 illustrates another method for manufacturing a fiber mat
facer according to an embodiment of the invention.

[0016] In the appended figures, similar components and/or features may
have the same numerical reference label. Further, various components of
the same type may be distinguished by following the reference label by a
letter that distinguishes among the similar components and/or features.
If only the first numerical reference label is used in the specification,
the description is applicable to any one of the similar components and/or
features having the same first numerical reference label irrespective of
the letter suffix.

DETAILED DESCRIPTION OF THE INVENTION

[0017] The ensuing description provides exemplary embodiments only, and is
not intended to limit the scope, applicability or configuration of the
disclosure. Rather, the ensuing description of the exemplary embodiments
will provide those skilled in the art with an enabling description for
implementing one or more exemplary embodiments. It being understood that
various changes may be made in the function and arrangement of elements
without departing from the spirit and scope of the invention as set forth
in the appended claims.

[0018] Embodiments of the invention provide fiber mat facers that may be
coupled with boards, such as ceiling panels to provide an aesthetic
appealing look and/or for other reasons. The fiber mat facers are
generally used in ceiling applications due to the visually appealing
appearance that they provide. The fiber mat facers have a flat,
gloss-free surface and may be attached to ceiling panels to provide a
corresponding appearance. The fiber mat facers also have a
non-directional visual appearance, meaning that the appearance of the
fiber mat facers is the same when viewed from any angle, or put another
way, the appearance does not depend on the angle in which the fiber mat
facer is viewed. In addition to enhanced visual appeal, the described
fiber mat facers and ceiling panels provide smooth, clean, durable
finishes that are washable, impact-resistant, scratch-resistant, soil
resistant, water repellant, and scrubbable. They also provide sound
absorption for sound blocking.

[0019] The fiber mat facers may include a blend of different sized fibers,
which may be made of glass. The blend of fibers may include large
diameter fibers that range in size between about 6 and about 25 μm,
and small diameter fibers or microfibers that range in size between about
0.5 and 5 μm. In a specific embodiment, the larger diameter fibers may
be about 11 μm diameter fibers and the microfibers may be about 3
μm in diameter. The fiber mat facers may also include a binder that
bonds the large diameter fibers and microfibers together to form the
fiber mat. The binder may be water repellant and/or include a water
repellant additive such as a stearylated melamine water repellant.

[0020] An additive, such as white pigment, may be added to the fiber mat
to increase the opacity of the mat. In some embodiments, the additive
(e.g., the white pigment) is blended with, or otherwise added, to the
binder and subsequently applied to the fiber mat, such as by applying the
binder via a curtain coater to non-woven or wet-laid web of fibers. The
additive (e.g., the white pigment) may enhance the light reflectance of
the fiber mat when compared to similar fiber mats that do not have the
additive.

[0021] Paint may be applied to an outer surface of the fiber mat facer to
provide a ceiling panel having a desired color and/or finish. The water
repellant binder and/or the microfibers may control or limit the
absorption of the paint into the fiber mat facer. This may allow a
controlled amount of paint to remain on the surface of the mat to provide
the flat, gloss-free appearance. The paint may also include an amount of
a weak acid that enhances the light reflectance and/or reduces the
yellowness of the mat and/or paint in order to provide the desired
appearance. These and other features of the invention will be more
evident with reference to the figures.

[0022] Exemplary Fiber Mat Facers

[0023] Referring now to FIG. 1, illustrated is a fiber mat facer 100 that
may be coupled with ceiling panels to enhance the visual appeal of the
boards, such as by providing a flat, gloss-free surface. Fiber mat facer
100 includes a non-woven web of fibers that are bonded together to form
the fiber mat. The non-woven web of fibers includes chopped continuous
glass fibers, that may be a blend of larger diameter fibers (e.g.,
chopped strand fibers, staple fibers) and smaller diameter fibers (e.g.,
microfibers). In one embodiment, the large diameter fibers may have fiber
diameters in the range between about 6 μm and about 20 μm. In other
embodiments, the fiber diameters may range between about 8 μm and
about 15 μm and/or between about 10 μm and about 13 μm. In a
specific embodiment, the average fiber diameter of the plurality of large
diameter fibers may be about 11 μm. The large diameter fibers may
comprise glass or other fibers, such as E glass, C glass, T glass, sodium
borosilicate glass, A & S glasses, Basalt, mineral wool, slag fiber, and
the like, and mixtures thereof. The large diameter fibers may strengthen
or reinforce the fiber mat.

[0024] As mentioned above, the non-woven web of fibers also includes a
plurality of microfibers, which in one embodiment, includes fiber having
diameters in the range between about 0.5 μm and about 5 μm. In
other embodiments, the fiber diameters may range between about 1 μm
and about 4 μm and/or between about 2 μm and about 3 μm. In a
specific embodiment, the average fiber diameter of the plurality of large
diameter fibers may be about 3 μm. In a specific embodiment, the
microfibers are biosoluble, such as type 481 glass manufactured and/or
sold by Johns Manville. The microfibers may include any of the fibers
listed above, such as glass fibers. The microfibers may provide fiber mat
facer 100 with a smooth appearance and/or provide a non-directional
visual appearance so that facer 100 has essentially the same appearance
when viewed from different angles. Mats without such microfibers may have
a visual appearance when viewed in the machine direction (i.e., a
direction aligned with the large diameter fibers) that is different from
a visual appearance in the cross-machine direction. The microfibers may
function as fillers between the large diameter fibers to provide the
non-directional appearance. The microfibers may also decrease the air
permeability of fiber mat facer 100, and allow for paint to remain on the
surface of facer 100 to improve or enhance the light reflectance of facer
100. Air permeability is usually measured in cubic feet per minute per
square foot of material at a fixed pressure of 0.5 inch H20 (i.e.,
cfm @1/2'' W.G.). The fiber mat facers 100 described herein may have air
permeability values ranging between about 300 and 500, and more commonly
between about 375 and 425. In some embodiments, the microfibers may be
biosoluble fibers, such as those described in U.S. Pat. No. 5,945,360,
titled "Biosoluble Pot and Marble-Derived Fiberglass" and U.S. Pat. No.
5,981,414, titled "Glass Fiber Composition with Improved Biosolubility",
the entire disclosures of which are incorporated herein by reference for
all purposes. These fibers may provide various health advantages over
other conventional fibers.

[0025] The fiber length of the larger diameter fibers and the smaller
diameter fibers used in the blend may be the same or different. Exemplary
fiber lengths of the coarse fibers may include length between about 6 mm
to about 18 mm while the smaller diameter fibers include lengths between
about 1 mm to 6 mm. The web of fibers may also include fibers that are
broken into two or more pieces and small glass fibers (e.g., less than 1
mm), chips, and flakes. Exemplary large diameter fibers include H117, a
wet chopped fiber product available commercially from Johns Manville Corp
under the trade name Chop-Pak®. The H117 fibers may have a fiber
length of approximately 12 mm. Exemplary small diameter fibers include
110X-481, a micro-strand fiber product available commercially from Johns
Manville Corp under the trade name Micro-Strand®. The larger diameter
fibers may make up more than half the total weight of the fiber blend in
the web. Exemplary quantities of the larger diameter fibers may include
about 60 wt. % to about 75 wt. % of the total dry weight of fiber mat
facer 100. In a specific embodiment, fiber mat facer 100 includes about
67 wt. %±2 wt. % of larger fibers. Exemplary quantities of the
microfibers may include about 5 wt. % to about 20 wt. % of the total dry
weight of fiber mat facer 100. In a specific embodiment, fiber mat facer
100 includes about 12 wt. %±2 wt. % of microfibers.

[0026] An organic or inorganic binder is usually added to the non-woven
web of fibers to bond the non-woven web of fibers together into fiber mat
facer 100. The binder may be formaldehyde free and may include epoxies,
polyvinyl acetate, Ethylene vinyl chloride, PVC, Polyesters, and the
like. In one embodiment, an acrylic thermoset is used due to its low
flammability, low cost, thermal stability, color fastness, and the like.
The binder may be an acrylic binder and may include a water repellant
additive that limits the absorption of water based materials into the
non-woven web of fibers, such as various paints. As with the microfibers
or as an alternative to the microfibers, the water repellant binder may
allow paint to remain on the surface of facer 100 to improve or enhance
the light reflectance of facer 100. In some embodiments, the amount of
absorption of paint within the non-woven web of fibers may be controlled
and/or varied by varying the amount of water repellant additive used in
the binder and/or by varying the amount of microfibers added to the
non-woven web of fibers. Exemplary amounts of binder in fiber mat facer
100, based on its dry weight, may range from about 15 wt. % to 30 wt. %.
In a specific embodiment, the amount of binder is about 20 wt. %±2.5
wt. %.

[0027] In some embodiments, the binder includes a
hexamethoxymethylolmelamine crosslinking agent, such as, for example,
those commercially available from Emerald Performance Materials under the
trade name Aerotex® 3030. In other embodiments, the
melamine-formaldehyde crosslinking agent is removed so that facer 100 is
essentially formaldehyde free and may be used in applications requiring
no formaldehyde added facers. In a specific embodiment, the binder
includes a stearylated melamine water repellant. In another embodiment,
paraffin and/or blends of stearylated melamine and paraffin may be used.
Other water repellents may be used such as micronized waxes, oleyl,
tallow, cetyl alcohol, and the like. Exemplary concentrations of the
stearylated melamine in fiber mat facer 100, based on its dry weight, may
range from about 0.4 wt. to 1.5 wt. %, with a specific embodiment
including about 0.6 wt. %±0.1 wt. %. In some embodiments, the binder
may also or alternatively include an amount of an anti-oxidant, such as
sodium tetrafluoroborate, BHT, EDTA, and the like. The sodium
tetrafluoroborate may reduce the yellowness of the non-woven web of
fibers in both a painted and unpainted state. Exemplary concentrations of
the sodium tetrafluoroborate in fiber mat facer 100, based on its dry
weight, may range from about 0.1 wt. % to 1.0 wt. %, with a specific
embodiment including about 0.4 wt. %±0.1 wt. %. Exemplary sodium
tetrafluoroborate products are available commercially from Shorechem,
LLC.

[0028] In some embodiments, the binder may include other additives, such
as flame resistant resinous binders such as urea formaldehyde, modified
urea formaldehyde, acrylic resins, melamine resins, homopolymers or
copolymers of polyacrylic acid; crosslinking acrylic copolymers (e.g.,
acrylic copolymers having a glass transition temperature (GTT) of at
least about 25° C.); crosslinked vinyl chloride acrylate
copolymers (e.g., copolymers having a GTT of about 113° C. or
less), among other types of binders. Flame retardants may also be
included in the binder, such as Alumina trihydrate, organic phosphonates,
Antimony oxide, and the like.

[0029] An additive, such as in the form of a dispersion or pigment, may
also be added to the non-woven web of fibers and/or the binder to enhance
the opacity of fiber mat facer 100. The enhanced opacity of facer 100 due
to the addition of the additive to the non-woven web of fibers and/or the
binder may improve the overall flat, gloss-free surface and/or appearance
of facer 100 compared to similar mats without the additive. In one
embodiment, the additive comprises white pigment that is added to the
binder and subsequently applied via a curtain coater to the non-woven web
of fibers. The non-woven web of fibers may be cured to form fiber mat
facer 100. Exemplary concentrations of the pigment or dispersion additive
in fiber mat facer 100, based on its dry weight, may range from about 0.5
wt. % to 2.0 wt. %, with a specific embodiment including about 1.0 wt.
%±0.1 wt. %. In a specific embodiment, a white pigment additive is
used, such as those available commercially from BASF SE, under the
tradename PureOptions KX White.

[0030] An outer surface of fiber mat facer 100 may include a paint or
paint coating having a defined color and/or finish, such as a flat,
gloss-free white color and finish. The paint may be applied to fiber mat
facer 100 either before or after facer 100 is coupled with a board, such
as on-site subsequent to installing the board in a structure. The paint
or paint coating may include a weak acid, such as sodium
tetrafluoroborate, boric acid, sodium hypochlorite, and the like. In one
embodiment, the paint includes a binder that is reactive with the weak
acid such that viscosity is increased by the weak acid addition. For
example, the viscosity at high shear, such as in a spray nozzle, may be
reduced to near that of the unmodified paint while at low shear the
viscosity is increased. The binder may be polyvinyl acetate or a similar
compound that provides the reaction with the weak acids. In one
embodiment, the weak acids may have a pKa between about -2 and 14, and
more commonly between about 4 and 12 or 9 and 12. The weak acid additive
in the paint or paint coating may increase the light reflectance of facer
100 and/or reduce a yellowness of facer 100 and/or the paint while
maintaining the flat, gloss-free surface and appearance of the painted
facer 100. Exemplary concentrations of weak acids that may be added to
the paint, based on the dry weight of the paint, are shown in the table
below.

[0031] Several additional exemplary embodiments of fiber mat facer 100 are
provided in the tables below. The exemplary fiber mat facers had a mat
basis weight in grams per square meter of between about 60 and 75 with an
average of about 68. Although several exemplary embodiments are provided,
the facers are not limited to these embodiments.

[0032] A paint may be added to the surface of any of the fiber mat facers
described above. For example, in an exemplary embodiment, paint is
applied to an outer surface of the 2nd exemplary fiber mat facer.
The paint may include an additive, such as the above identified weak
acids, that enhances the visual appeal of the fiber mat facer. The amount
of the weak acid added to the paint may be within the ranges specified
previously.

[0033] Referring now to FIG. 2, illustrated is a perspective view of a
faced ceiling panel 200 including a ceiling panel composite 202 and a
fiber mat facer 100 overlaying and bonded to one surface of composite
202. Fiber mat facer 100 may be any of the facers described herein and
may enhance the visual appeal of ceiling panel 200. Composite 202 may be
a high-density polymer or predominantly polymer material or foam material
core layer. Facer 100 may be substantially coextensive with, coextensive
with, or extend beyond the major surface of composite 202. In one
embodiment, composite 202 is made of glass wool, mineral wool,
fiberboard, wood fibers, gypsum, and the like.

[0034] Exemplary Methods

[0035] Referring now to FIG. 3, illustrated is a method 300 for
manufacturing a fiber mat facer. At block 310, a first and second group
of fibers may be blended to form a non-woven web of fibers. The first
group of fibers may have an average fiber diameter of about 6 μm to
about 20 μm, while the second group of fibers may have an average
fiber diameter of about 0.5 μm to about 5 μm. In a specific
embodiment, the first group of fibers have an average fiber diameter of
about 11 μm while the second group of fibers have an average fiber
diameter of about 3 μm. An exemplary technique for the blending may
include the forming of a slurry (e.g., an aqueous slurry) with the
fibers. The fiber slurry may then be mechanically agitated to dispense
the fibers more homogeneously through the slurry. Following the
agitation, the slurry may be dispensed on a moving screen. A vacuum may
be applied to remove a substantial part of the aqueous solution, which
may be recycled into more solution for the slurry. With a substantial
portion of the aqueous solution removed, the non-woven web of fibers is
formed on the moving screen.

[0036] At block 320, the non-woven web of fibers may then be contacted
with a binder solution 204 to form a wet mat. The binder solution may be
an aqueous binder solution applied to the web using, for example, a
curtain coater or a dip-and-squeeze applicator. Excess binder solution
may pass through the screen supporting the binder-coated wet mat. The
binder may be any of the binders and/or include any of the additives
described herein. For example, the binder may include a water repellant
additive (e.g., stearylated melamine), a pigment or dispersion additive
(e.g., white pigment), sodium tetrafluoroborate, or other antioxidants,
and the like.

[0037] At block 330, the wet mat may then be cured to form a fiber mat.
Exemplary curing techniques may include heating using thru air dryers,
flotation dryers, steam drums, oil heated drums, among other techniques.
Continuing with the moving screen technique described above, heat may be
applied following the removal of excess binder through the web of fibers
to evaporate any remaining water and cure the polymer precursors in the
binder solution into a polymerized binder that bonds together the fibers.
The heat source may be an oven through which the wet mat is conveyed on
the moving screen.

[0038] In some embodiments, the process of manufacturing the
fiber-reinforced mat may be a continuous process, with the moving screen
providing a continuous, conveyor-like loop that may be on a slight upward
incline while the fiber slurry is deposited thereon. Subsequently, the
excess slurry solution is removed and the non-woven web of fibers is
conveyed to an area where binder solution is applied. Following the
spraying, curtain coating, etc., of the binder solution, the wet mat is
conveyed on the moving screen through an oven for the drying of the mat
and polymerization of the binder. Exemplary heating conditions may
include subjecting the wet mat to temperatures of about 120° C. to
about 330° C. for periods of, for example, 1 to 2 minutes, less
than 40 seconds, etc. The final mat may have a thickness of, for example,
about 10 mils to about 30 mils.

[0039] Referring now to FIG. 4, illustrated is another method 400 for
manufacturing a fiber mat facer. Method 400 is similar to method 300 in
that at block 410 large diameter fibers and microfibers are blended to
form a non-woven web of fibers, which web of fibers is contacted at block
420 with a binder solution to form a wet mat. Similarly, at block 430,
the wet mat is cured to form a fiber mat. Method 400 is different than
method 300 in that it includes the additional steps of contacting the
fiber mat with an opacity enhancing additive (block 440) and applying
paint to an outer surface of the fiber mat (block 450). The step of
contacting the fiber mat with an opacity enhancing additive (block 440)
is an optional step that may be performed if the binder does not include
an opacity enhancing additive, such as white pigment, or as an additional
step even if the binder does include such additive. The step of
contacting the fiber mat with an opacity enhancing additive may be
performed by applying the additive via a curtain coater, dip process, and
the like, or adding the additive to the slurry of blended large and small
fibers. Typically, however, the opacity enhancing additive is included in
the binder and step 440 is not performed.

[0040] The step of applying paint to an outer surface of the fiber mat
(450) may be performed to provide a desired color and/or finish to the
final fiber mat facer, such as to provide a flat, gloss-free finish. The
paint may be applied via roll coating, knife coating, spraying, and the
like. As described herein, the microfiber and/or water repellant binder
composition of the fiber mat may limit the amount of absorption of the
paint into the fiber mat so that a portion of the paint remains on or
near the outer surface of the fiber mat to improve the brightness and/or
light reflectance of the mat and provide the desired flat, gloss-free
surface and appearance. The amount of paint that remains on the surface
may be controlled or varied by varying the composition of the microfibers
and/or water repellant binder. For example, control may be provided by
selection of repellent chemistry and/or dispersant chemistry in the
binder to achieve a surface energy of between about 40 dyne/cm and 50
dyne/cm, and more commonly about 45 dyne/cm. In one embodiment, the
binder chemistry may be selected so that the dispersive and polar
components of the surface energy may be balanced at an approximate ratio
of 2:1 to provide one or more of the desired facer characteristics
described herein. In a specific embodiment, the binder chemistry includes
a dispersive component of about 30 d/cm and a polar component that ranges
between about 10 and 20 d/cm so that the approximate ratio of 2:1 is
provided. The exemplary compositions described herein, however, are
sufficient to provide the desired flat, gloss-free surface and
appearance.

[0041] Method 400 may further include the step (not numbered) of mixing an
additive (e.g., the described weak acids) with the paint prior to
applying the paint to the outer surface of the fiber mat. The weak acids
mixed with the paint may include sodium tetrafluoroborate, boric acid,
sodium hypochlorite, and the like. These additives may improve the light
reflectance of the fiber mat facer and/or reduce yellowness of the fiber
mat facer so as to enhance the visual appeal of the fiber mat facer.
These additives may be added in the amounts described herein, which are
sufficient to enhance the visual appeal of the resulting fiber mat
facers. The fiber mat facers described in or produced by methods 300 and
400 may be coupled with a ceiling panel and subsequently installed in a
building or structure to provide enhanced visual appeal to the building
or structure.

[0042] Having described several embodiments, it will be recognized by
those of skill in the art that various modifications, alternative
constructions, and equivalents may be used without departing from the
spirit of the invention. Additionally, a number of well-known processes
and elements have not been described in order to avoid unnecessarily
obscuring the present invention. Accordingly, the above description
should not be taken as limiting the scope of the invention.

[0043] Where a range of values is provided, it is understood that each
intervening value, to the tenth of the unit of the lower limit unless the
context clearly dictates otherwise, between the upper and lower limits of
that range is also specifically disclosed. Each smaller range between any
stated value or intervening value in a stated range and any other stated
or intervening value in that stated range is encompassed. The upper and
lower limits of these smaller ranges may independently be included or
excluded in the range, and each range where either, neither or both
limits are included in the smaller ranges is also encompassed within the
invention, subject to any specifically excluded limit in the stated
range. Where the stated range includes one or both of the limits, ranges
excluding either or both of those included limits are also included.

[0044] As used herein and in the appended claims, the singular forms "a",
"an", and "the" include plural referents unless the context clearly
dictates otherwise. Thus, for example, reference to "a process" includes
a plurality of such processes and reference to "the device" includes
reference to one or more devices and equivalents thereof known to those
skilled in the art, and so forth.

[0045] Also, the words "comprise," "comprising," "include," "including,"
and "includes" when used in this specification and in the following
claims are intended to specify the presence of stated features, integers,
components, or steps, but they do not preclude the presence or addition
of one or more other features, integers, components, steps, acts, or
groups.